Chapter 11
MDP-621/641/640
Trouble
Shooting
Operation
manual
(Plotter)
Faults detected
Possible cause of the failure
Remedial action against negative
result
Own ship’s position is not
shown in the screen.
1. Confirm if the cross cursor is
displayed in the screen. If the
cross cursor is displayed, the
screen is set to VIEWPOINT
mode. In this case own ship line
beyond the screen cannot be
brought in the screen.
1. Delete the cross cursor display
from the screen and press the
joystick to move own ship to a
desired position within the
screen.
Own ship’s mark does
not blink and no position
fix is available
1. Select NAV MENU
→
GPS
MONITOR. If the GPS CLOCK
item is shown without data, it
indicates no GPS data supplied
from GPS sensor.
2. If the GPS CLOCK item is shown
with the time, the GPS signals
from the satellites are not properly
received.
1. Check the connection of the
GPS cable.
2. Check the position of the GPS
antenna and correct, if
necessary.
Own ship’s position
(lat/lon) is deviated from
actual position on the
chart.
1. Check if the position correction
mark is shown. If it is shown,
position correction is in effect.
1. Undo this function by the
following method: Select Plotter
MENU
→
Setup
→
Chart
Correction and incorporate
position corrections.
Old ship’s track is
erased.
1. Check if the number of plots
shown in the right bottom of the
screen has reached the maximum
7000. If YES, the oldest track is
erased on a first-in first-out basis.
1. You should save an important
track record by referring to
Para10.3.3.1 –(3) “TRACK
STORE”.
(Radar)
Faults detected
Possible cause of the failure
Remedial action against negative
result
Targets are weak
1. Tuning has drifted.
2. Magnetron or MIC is faulty.
1. Re-adjust tuning referring to
Para 10.4.6.3 “Adjusting the
tuning circuit”.
2. Call for service.
Echo image on screen
differs from actual image.
1. Ship heading is incorrectly set.
2. Timing adjustment is incorrectly
set.
1. Re-adjust heading referring to
Para 10.4.6.2 “Adjusting the
angle”.
2. Re-adjust timing referring to
Para 10.4.6.1 “Adjusting the
distance”.
Too much noise.
1. Tuning has drifted.
2. Radar is not properly grounded.
1. Re-adjust tuning referring to
Para 10.4.6.3 “Adjusting the
tuning circuit”.
2.
Connect grounding wire to
ship’s bonding or grounding
system.
Aerial does not rotate.
1. Motor fuse is blown.
2. Turning motor is not powered.
3. Turning motor brushes are worn
out.
1. Replace the motor fuse with
new one.
2. Check the connections for motor
power supply line.
3. Replace the motor brushes.
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